fix(meta): send a bid strategy Graph will accept without a bid amount

With the campaign-level field fixed, the live run got one object further
and failed on the ad set: "Bid amount or bid constraints required for bid
strategy" (code 100, subcode 2490487). We were sending no bid_strategy at
all, and Graph requires one on every ad set that carries its own budget —
which, since MaskanX never uses campaign budget, is all of them.

LOWEST_COST_WITHOUT_CAP is the only strategy that needs nothing else from
us: COST_CAP and LOWEST_COST_WITH_BID_CAP need a bid amount, and
LOWEST_COST_WITH_MIN_ROAS needs bid constraints plus a VALUE optimisation
goal. CampaignSpec carries none of those, so the allowlist holds exactly
one value and build_ad_set_payload refuses the rest before any network
call — a rejection at sync time would land after the campaign object
already exists, leaving a half-built chain behind.

It also suits the guardrails: automatic bidding spends the daily budget
and never exceeds it, where the cap strategies bound unit price rather
than total spend.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/adclaw/meta/client.py

@@ -430,6 +430,7 @@ class MetaClient:
         targeting: dict[str, Any],
         optimization_goal: str,
         billing_event: str,
+        bid_strategy: str = "LOWEST_COST_WITHOUT_CAP",
         status: str = CREATE_STATUS,
     ) -> str:
         """Create a paused ad set and return its id.
@@ -453,6 +454,9 @@ class MetaClient:
                 "targeting": json.dumps(targeting),
                 "optimization_goal": optimization_goal,
                 "billing_event": billing_event,
+                # Required whenever the ad set carries its own budget, which
+                # is always here. Omitting it is code 100 / subcode 2490487.
+                "bid_strategy": bid_strategy,
                 "status": CREATE_STATUS,
             },
         )

src/adclaw/meta/objects.py

@@ -52,6 +52,25 @@ from ..campaigns.models import CampaignSpec
 DEFAULT_OPTIMIZATION_GOAL = "LEAD_GENERATION"
 DEFAULT_BILLING_EVENT = "IMPRESSIONS"
 
+# Graph requires a bid strategy on every ad set that carries its own budget,
+# and every strategy except this one additionally requires a bid amount or
+# bid constraints. Sending nothing is rejected with code 100 / subcode
+# 2490487, which is what blocked the first live sync.
+#
+# LOWEST_COST_WITHOUT_CAP is automatic bidding: Meta spends the daily budget
+# as efficiently as it can and never exceeds it. The alternatives set a
+# per-result ceiling instead, which controls unit price but not total spend
+# — the opposite of what the guardrails need.
+DEFAULT_BID_STRATEGY = "LOWEST_COST_WITHOUT_CAP"
+
+# Only one strategy needs nothing else from us. COST_CAP and
+# LOWEST_COST_WITH_BID_CAP need a bid amount; LOWEST_COST_WITH_MIN_ROAS
+# needs bid_constraints plus a VALUE optimisation goal. CampaignSpec
+# carries none of those, so accepting any of them here would just recreate
+# subcode 2490487 at sync time — after the campaign object already exists.
+# Widen this only together with the fields the strategy requires.
+ALLOWED_BID_STRATEGIES = frozenset({"LOWEST_COST_WITHOUT_CAP"})
+
 # advanced.optimization_goal / advanced.billing_event are client-controlled
 # and billing_event determines how the ad account is charged, so both are
 # checked against an allowlist before being forwarded to a spending API.
@@ -141,6 +160,14 @@ def build_ad_set_payload(spec: CampaignSpec, campaign_id: str) -> dict[str, Any]
             f"{sorted(ALLOWED_BILLING_EVENTS)}",
         )
 
+    bid_strategy = spec.advanced.get("bid_strategy", DEFAULT_BID_STRATEGY)
+    if bid_strategy not in ALLOWED_BID_STRATEGIES:
+        raise ValueError(
+            f"Unsupported bid_strategy {bid_strategy!r}. Allowed: "
+            f"{sorted(ALLOWED_BID_STRATEGIES)}. The others require a bid "
+            f"amount or bid constraints, which CampaignSpec does not carry.",
+        )
+
     return {
         "campaign_id": campaign_id,
         "name": f"{spec.name} - Ad Set",
@@ -148,6 +175,7 @@ def build_ad_set_payload(spec: CampaignSpec, campaign_id: str) -> dict[str, Any]
         "targeting": targeting,
         "optimization_goal": optimization_goal,
         "billing_event": billing_event,
+        "bid_strategy": bid_strategy,
     }
 
 

tests/test_meta_writes.py

@@ -602,3 +602,52 @@ async def test_adset_budget_sharing_is_off_by_default_but_overridable():
 
     assert transport.calls[0]["params"]["is_adset_budget_sharing_enabled"] == "false"
     assert transport.calls[1]["params"]["is_adset_budget_sharing_enabled"] == "true"
+
+
+# ---------------------------------------------------------------------------
+# bid strategy: the field Graph requires on a budget-carrying ad set
+# ---------------------------------------------------------------------------
+
+
+def test_build_ad_set_payload_defaults_to_automatic_bidding():
+    """Graph rejects an ad set that carries its own budget and no strategy.
+
+    Code 100 / subcode 2490487 — the failure that stopped the live sync
+    once the campaign-level one was fixed. LOWEST_COST_WITHOUT_CAP is the
+    only strategy needing no bid amount from us, and it never exceeds the
+    daily budget, which is what the guardrails assume.
+    """
+    payload = build_ad_set_payload(_spec(), campaign_id="c1")
+
+    assert payload["bid_strategy"] == "LOWEST_COST_WITHOUT_CAP"
+
+
+def test_build_ad_set_payload_refuses_a_strategy_that_needs_a_bid_amount():
+    """These would be accepted here and rejected by Meta *after* the
+    campaign object exists, leaving a half-built chain in the account.
+    Refusing before the first network call keeps it clean."""
+    for strategy in (
+        "COST_CAP", "LOWEST_COST_WITH_BID_CAP", "LOWEST_COST_WITH_MIN_ROAS",
+    ):
+        spec = _spec(advanced={"bid_strategy": strategy})
+        with pytest.raises(ValueError, match="bid_strategy"):
+            build_ad_set_payload(spec, campaign_id="c1")
+
+
+@pytest.mark.asyncio
+async def test_create_ad_set_sends_the_bid_strategy():
+    transport = FakeTransport([{"id": "set_1"}])
+    client = MetaClient(access_token="tok", transport=transport)
+
+    await client.create_ad_set(
+        "act_1",
+        campaign_id="c1",
+        name="Set",
+        daily_budget=5000,
+        targeting={"geo_locations": {"countries": ["IN"]}},
+        optimization_goal="LEAD_GENERATION",
+        billing_event="IMPRESSIONS",
+    )
+
+    sent = transport.calls[0]["params"]["bid_strategy"]
+    assert sent == "LOWEST_COST_WITHOUT_CAP"